Your kitchen sink and faucet may look spotless but there’s a hidden spot that harbors germs and residue. It’s the screen where the water flows from the faucet. It should be removed and cleaned periodically. To do, unscrew the metal aerator from the faucet and soak in a mixture of one gallon of warm water and 1/2 cup of borax for at least one half hour. Scrub with a clean toothbrush, rinse, and replace.